Carburetor



Oct. 11, 1927.

5 Sheets-Sheet 1 CARBURETOR A. MOORHOUSE Filed April 50, 919

()ct- 1927' A. MOORHOUSE CARBURETOR Filed April 50, 1919 5 Sheets-Sheet 2 Oct. 1 1 1927.

1,645,341 A. MOORHOUSE CARBURETOR Filed April 30, 1919 5 Sheets-Sheet 3 Oct. 11, 1927.

A. MOORHOUSE CARBURETOR Filed April 50, 1919 5 Sheets-Sheet 4 06L 1927' A. MOORHOUSE CARBURETOR 5 Sheets-Sheet 5 Filed April 50, 9

Patented Oct. 11, 1927.

UNITED STATES 1,645,341 PATENT OFFICE.

ALFRED IQOBHOUSE, OF DETROIT, MICHIGAN, ASSIGNOR '10 PACKARD MOTOR GAB COHPANY, OF DETROIT, MICHIGAN, A QORPORATION OF MICHIGAN.

GABBURETOR.

Applldation filled April 30, 1919. Serial No. 298,628.

This invention relates to improvements in carburetors.

The carburetor is of the down draft type. One object of the invention is to provide means to prevent flooding of the carburetor.

Another object of the invention is to provide means for producing an emulsion of liquid fuel and air previous to the formation of the final explosive mixture within the main mixing chamber of the carburetor- Another object of the invention is to provide means for intensifying the suction ac tion through the carbureting elements.

Another object of the invention is to provide means for obtaining a graduating action between the main fuel jet and what is known as the compensating supply which is adapted to balance an increasingly r1ch mixture from the main jet with an increasingly lean mixture from the compensating means. Other objects of the invention will appear from the disclosure in the following specification.

With these objects in view the invention is embodied in preferable form in the construction and arrangement hereinafter described and illustrated in the accompanying drawings, in which Fig. 1 is a perspective view, partly broken 80 away to show some of the interior construction in vertical section.

Fig. 2 is a side view, partly broken away, and showing a sect-ion on line 22 of Fig. 4, with, however, the Venturi tubes in place. Fig. 3 is a vertical section taken on line 33 of Fig. 4, but with the positions of the views reversed.

Fig. 4 is a partial plan and partial hori= zontal section on line 4-4 of Fig. 2. Fig. 5 is an end view, partly broken away. Fig. 6 is a vertical section on line 6-6 of Fig. 4. I

Referring to drawings, 10 is a float of usual construction which is mounted in a float chamber 11. An inlet 12 serves to conduct liquid hydrocarbon fuel to said chamber from a suitable source of supply and leads through a chamber 13 and a strainor 14 mounted in said latter chamber. An inlet bushing 15 provides a passage-way between the strainer chamber and the float chamber and such inlet passage way is controlled by a needle valve 16, operable by the float. Outlet passage-ways 17 lead from the float chamber through the body of the carburetor to two basin plugs 18 and 19 located in tlhe bottom of wells 20 and 21 respec- 1ve y.

The well 20 contains a tube 24 for feeding the jet which is subject to the suction ofthe engine, while the well 21 constitutes a gravity feed well and is open to the atmosphere. This latter well also contains a tube indicated at 42, which supplies the necessary fuel to the engine at idling speeds thereof. The plugs 18 and 19 are threaded in the lower end of that portion of the body of the carburetor which includes the two wells referred to. Above the plug 18 is a calibrated restricting plug. 22 which has a small opening at 23 thereto that determines the quantity of the gasoline passing through the passageway into the jet tube 24. This tube is subject to the suction of the engine and the fuel therefrom is drawn out of the well 20 into the horizontal passage-Way 25 and thence through vertical passage-way 26 and horizontal passage-way 27. This\ passage communicates with a head 28 provided with an annular recess 29 communicating with the openings 30 formed in a Venturi tube 31 which is carried by said head and has its upper end open to the atmosphere and its lower end terminating within an open Venturi tube 32. The fuel feeding holes 30 are located at the line of greatest contraction of the Venturi tube 31 to thereby increase the intermingling force of the air and emulsion. This point of emer- ..g ence of the fuel into the tube and also the ,level of the supply passage-way 27 are above 'the level of the fuel in the float chamber, whereby flooding of the carburetor-is prevented. The lower end of the tube 31 terminates at the line of greatest contraction of the tube 32 whereby the latter exerts an ejector action on the former, thereby in- .creasing the velocity head through the con- ;tracted part of the small tube. In this way a' higher degree of atomization is accomplished in the small tube and there is suflicient suction to raise the fuel from the float chamber 11. I i

Below the lower end of the Venturi tube 32 is mounted a throttle valve 33 of the butterfly type. This valve is located in chamber 34 and is operated by shaft 35.

Referring to Figs. 1 and 6, the well 21 is provided with a screw plug 36 having a calibrated opening 37 there-through. This well 21 is o n to the atmosphere through passage 38 see Fig. 1), which leads back to the annular chamber 39 surrounding the venturi 32 and which chamber is open to the atmosphere. Owing to this arrangement the fuel in the tube 21 is dependent for its height merely upon the head of the fuel in the fuel chamber. The well 21 communicates by a series of openings 40 arranged at different heights, and having different cross areas, with the well of the main jet and liquid fuel is supplied to the latter well through these openings up to the height of the fuel in the float chamber and as the level of the fuel falls these openings will be successively uncovered and successively permit air to' be drawn there-through from t e well 21 so as to decrease the rich- .ness of the mixture of the fuel supplied from wells 21 and 20. The openings are adapted to be conveneiently drilled through openings provided in the outer wall of the well 20 and which are adapted to be closed by the screw plugs 41.

Mounted in the well 21 is an idling tube 42 adapted to supply fuel at idling speeds nular passage 46. Since the of the engine. The lower end of this tube dips into the lower part of the well 21 and the upper end of the tube is held in a valve head 43 which is adjustable and is screwed within a bushing 44, which in turn is,

screwed to the body of the carburetor. The lower part 45 of said head constitutes a valve and is adapted to seat against a beveled ledge in the bushing 44 in order 1;?) close ofl the well 21. Between said valve and the wall of the bushing is left an annular space 46 adapted to admit air from the well to the assage-ways leading to the throttle and which space is cut off; when the valve is moved down against its seat. Openings 47 lead from the tube 42 int o said space 46 and through the bushing to per it the assage of liquid fuel from the tube 4 into a orizontal passage-way 47 The passage-way 47 leads to a vertical passageway-48 which communicates with a passage'49, (see Figs. 6, 5 and 1) which leads to a point opposite the edge of the throttle valve when t e latter is in closed position. When thegibutterfly valve is entirely closed it sealsthe outlet of passage 49 (see Fig. 1). When such valve is slightly opened, assuming that the engine is running, a high vacuum is produced, resulting in air blowing past the edge of the valve at a very high velocity, thus causing a high suction on passage 49. This suction is transmitted to passages 48 and 47 to holes 47 in the valve 45, as well as to anavity feed com ensating well 21 is full of uel up to the level maintained by the float, fuel is consequently sucked up the tube 42 through the past the valve seat and space and fuel which is drawn valve is screwed tight against its seat so as to close the space 46, only fuel will be drawn through the holes 47. If the valve be screwed out considerably, the annular passage 46 at the valve seat will be made suf ficiently large to satisfy the suction in the passage 47 so that only air will be drawn in. It will thus be seen that an intermediate position of the valve 45 can be readily obtained which will give'fhe correctly proportioned quantities of air and liquid liydrocarbon to provide the rich emulsion desired, which is then mingled with the air drawn past the butterfly valve 33, to form the necessary small amount of explosive mixture to maintain the engine running atidli-n-g speed. The upper edge 'of the valve head '43'i's serrated and is adapted to be engaged by a spring catch 50 (see Fig. 4). Y

51 1s a hollow rotary altitude valve (see Figs. 2 and 3), having a port 52 adapted to establish communication between the atmosphere and passage-way 26. The function of this valve is to bleed air into the? passage 27 through passage 26, when em loyed on an engine operatin at high al itudes, to relieve somewhat t e suction existing. in chamber or well 20, and thus weaken the mixture. The invention is shown as applied to a duplex carburetor consisting of two sets of carbureting elements and provided with two throttle valves and two manifold connecting passage-ways so that a separate supply of explosive mixture will be supplied separately to the two sets of cylinders of a V-type motor. The description heretofore has related solely to the carbureting elements of one-half of such duplex carburetor.

The shafts 35 of the two throttle valves carry toothed sectors 53 which mesh with one another so that when one of the shafts is turned as by the lever 54, the throttles will be turned in unison.

In order to prevent an accumulation of liquid fuel if the carburetor is flooded, a drain passage 55 leads from the upper part of the float chamber to the annular space 56 surrounding the outer venturi. The wall of this annular space isprovided with a tapped hole 57 adapted to. receive a pipe connection fora drain pipe, which may lead outside of the motor and away from the body or fuselage.

The operation of the carburetor is as fol lows Assuming that the engine is running idle, the throttle valve 33 is slightly open, and air passes the edge of the throttle valve at thus increasing the suction, the liquid fuel high velocity. The valve is so nearly closed, however, that there is ve little suction through the Venturi tubes 0 the carburetor, but there is considerable suction in the passageways 49, 48 and 47. Thus liquid fuel is drawn into the tube 42 from the well 21 and air isbdrafivn from thesweil 21 whicl is en lied t e assage 3 t e propor 1on 'of liquid f uel arid air being regulated by means of the adjustable valve head 43. This very rich mixture is, of course, diluted to some extent by the air passing the throttle valve 33, and thus a correct idling mixture is fed to the engine.

As the throttle valve 33 is opened, the main channels for feeding the mixture come into operation because the suction through the Venturi tube 31 is then suflicient to draw the emulsion of fuel through the main passages 25, 26 and 27. Until the level in the well 21 falls below the upper port 40, raw liquid will be drawn both from the wells 20 and 21 into the passage 25, but, of course, the upper port 40 is almost immediately uncovered and it then supplies air which it receives from the port 38, to the well 20, thus forming an emulsion which passes into the passageway 25 and thence through passages 26 and 27 to the Venturi tube 31.

As the throttle valve is opened still farther,

in the well 21 is soon exhausted because the restricted passage 37 supplies the well by gravity only, or substantially so, due to the atmospheric port 38 at the top of the well. Then all of the ports 40 are uncovered and are supplying air to the well 20. The latter well is under the full suction of the Venturi tube 31, except, of course, for the air fed to it through the ports 40, and an increasing amount of liquid fuel is drawn from the tube 24 for emulsion in the well 20 and the passage 25.

From the above it will be seen that the increasing suction on the well 20 tends to increase the liquid fuel fed to the carburetor,

and if this well operated alone, the mixture would be too rich at the higher suctions, but the higher suctions soon drainthe well 21 and the latter, therefore, supplies a constantly decreasing amount of liquid fuel relative to air and the net result is a substantially constant proportion of liquid fuel and air formed by the carburetor.

It will be understood further that at the lesser throttle openings the well 21 furnishes a reservoir of fuel for suppl ing the engine While idling, and it also elps to maintain a rather rich mixture for rapid acceleration.

Also, as has been pointed out hereinabove, air ma be bled into the passage 26 through the 1101 ow valve 51, which has been described as an altitude valve since its principal use is for operating-the carburetor in the higher altitudes where the air is less dense.

Having thus described my invention, what I claim and desire by Letters Patent is 1. In a carburetor, in combination with a float chamber, a mixing chamber for eflect= ing final carburetion of the air, a down draft Venturi tube in said chamber including means to admit air and vapor thereto for commin ling, the point of said commingling bemg located above the level of the fuel in the float chamber.

2. In a down draft carburetor, in combination with'a float chamber, a liquid fuel supply, a throttle, an upwardly rising liquid fuel tube, a venturi having communication with said tube at the upper end of the latter, said end of the tube being above the level of the said fuel supply.

3. In a down draft carburetor, a throttle valve, a float chamber,an upwardly conducting fuel conduit leading from the chamber, a downwardly conducting venturi leading toward the throttle valve and means to admit fuel from the upper end of the conduit to the venturi.

4. In a carburetor, in combination, means for producing an emulsion of liquid fuel and air, a down draft venturi a apted to receive additional air, and means to admit said emulsion to the venturi to form an explosive mixture with the air therein.

5. In a carburetor, means providing a down draft air passage, a venturi positioned therein, an up draft passage, means to form an emulsion of fuel and air in said up draft passage, and means including a second Venturi to discharge the emulsion into the down draft passage.

6. In a carburetor, in combination with a gravity feed well, an idling tube therein for conveying liquid fuel, a passage-way subject to the suction of the engine, a means of communication between said well and said passage-way and between the tube and the passage-way, a valve for controlling said communication and for proportioning the relative quantities of air and fuel passing from said tube and well to said passage-way.

-7. In a carburetor, in combination with a gravity feed well, a fuel conveying tube within said well, means of commumcation between said well and the atmosphere, a passage-way subject to the suction of the engine, means of communication between said tube and said passage-way consisting of an openingthrou h the tube, an annular opening between t ewall of the well and said passage-way and an adjustable valve for controlling the size of said annular opening, said opening having communication with said tube opening and with said passageways.

8. In a carburetor, in combination with a source of an 1 a avity feed well, a float chamber iii zdmm l nication therewith, a drainage chamber open to the atmosphere. a passageway between the upper part of said float chamber and said drainage chamher and a passa eway leadin from the upper part of sai gravity fee well to sa1d drainage chamber. I

9. Ina carburetor, in combination with idling and main jet wells, a souree of li uid fuel supply in communication therewi a drainage chamber and air connections from said wells to said drainage chamber.

10. In a down draft carburetor, in combination with a float chamber, a main jet well and an idling well, a drainage chamber open to the atmosphere and air connections between said wells and float chamber and said drainage. chamber.

11. In a carburetor, a float chamber, a gasoline passage leading from the bottom of the float chamber upwardly, a down draft venturi, said passage leading to the venturi a float chamber; a drainage chamber adjacent to said float chamber, a fuel well supplied by said float chamber, a carbureting chamber, means providing a passage leading from said fuel well to said carburetin chamber, and means providing a valve opening between said drainage chamber and said passage.

13. In a carburetor, the combination of a mixin chamber, a drainage chamber surroundmg the mixing chamber and open to the atmosphere, :1 float chamber, idling and main jet wells connected to be supplied by said float-chamber and communicating with said mixing chamber, and air connections between said drainage chamber and each of said wells and said float chamber.

In testimony whereof I aflix my signature.

ALFRED MOORHOUSE. 

